Piping systems exist to facilitate the flow of fluids (e.g., liquid, steam, gas (such as air) or plasma). For example, homes, schools, medical facilities, commercial buildings and other occupied structures generally require integrated piping systems so that water and/or other fluids can be circulated for a variety of uses. Liquids and/or gases such as cold and hot water, breathable air, glycol, compressed air, inert gases, cleaning chemicals, waste water, plant cooling water and paint and coatings are just some examples of the types of fluids and gases that can be deployed through piping systems. Tubing and piping types can include, for example, copper, stainless steel, CPVC (chlorinated polyvinyl chloride) and PEX (cross-linked polyethylene). For purposes of the present disclosure, the terms “pipe”, “piping”, “tube” or “tubing” will be understood to encompass one or more pipes, tubes, piping elements and/or tubing elements, and may be used interchangeably.
Piping connections are necessary to join various pieces of pipe and must be versatile in order to adapt to changes of pipe direction required in particular piping system implementations. For example, fittings and valves may be employed at the ends of open pieces of pipe that enable two pieces of pipe to fit together in a particular configuration. Among fitting types there are elbows, “tees”, couplings adapted for various purposes such as pipe size changes, ends, ball valves, stop valves, and partial angle connectors, for example.
In the past, pipe elements have been traditionally connected by welding and/or soldering them together using a torch. Soldering pipe fittings can be time-consuming, unsafe, and labor intensive. Soldering also requires employing numerous materials, such as copper pipes and fittings, emery cloths or pipe-cleaning brushes, flux, silver solder, a soldering torch and striker, a tubing cutter and safety glasses, for example. The process for soldering pipes can proceed by first preparing the pipe to be soldered, as the copper surface must be clean in order to form a good joint. The end of the pipe can be cleaned on the outside with emery cloth or a specially made wire brush. The inside of the fitting must be cleaned as well. Next, flux (a type of paste) can be applied to remove oxides and draw molten solder into the joint where the surfaces will be joined. The brush can be used to coat the inside of the fitting and the outside of the pipe with the flux. Next, the two pipes are pushed together firmly into place so that they “bottom out”—i.e., meet flush inside the fitting. The tip of the solder can be bent to the size of the pipe in order to avoid over-soldering. With the pipes and fitting in place, the torch is then ignited with the striker or by an auto-strike mechanism to initiate soldering. After heating for a few moments, if the copper surface is hot enough such that it melts when touched by the end of the solder, the solder can then be applied to the joint seam so that it runs around the joint and bonds the pipe and fitting together.
In recent years, push-fit technology has been employed with piping systems, and particularly with plumbing systems, to reduce the dangers and time involved in soldering joints and other connection methods. Push-fit methods require minimal knowledge of pipe fittings and involve far fewer materials than soldering. For example, one may only need the pipes, quick-connect fittings, a chamfer/de-burring tool and tubing cutter in order to connect pipes using push-fit technology. The steps involved in connecting piping systems using push-fit technology can be outlined as follows. First, the pipe is cut to the appropriate length and the end of the pipe is cleaned with the de-burring tool. Then the pipe and fitting are pushed together for connection. The fitting is provided with a fastening ring (also called a collet, grip ring or grab ring) having teeth that grip the pipe as it is inserted. The fastening ring device is employed to provide opposing energy, preventing the device from disconnection while creating a positive seal. Accordingly, no wrenches, clamping, gluing or soldering is involved. Push-fit and/or quick-connect technology for piping systems can be obtained, for example, through Quick Fitting, Inc. of Warwick, R.I., USA, suppliers of the CoPro®, ProBite®, LocJaw™, BlueHawk™ CopperHead® and Push Connect® lines of push fittings and related products. Also, such technology is described, for example, in U.S. Pat. No. 7,862,089, U.S. Pat. No. 7,942,161, U.S. Pat. No. 8,205,915, U.S. Pat. No. 8,210,576, U.S. Pat. No. 8,398,122, U.S. Pat. No. 8,480,134, U.S. Pat. No. 8,844,974, U.S. Pat. No. 8,844,981, U.S. Pat. No. 9,068,680, and U.S. Pat. No. 9,217,529, the disclosures of which are incorporated herein by reference in their entireties.
Among other specific issues, push fitting technologies generally have no stopping force for resisting or preventing the rotation of the fitting about an inserted tubing element. In various applications, such as with hard materials including stainless steel and copper, it is desirable to prevent the fitting from rotating about the inserted tubing element for stability, strength, durability and overall operation.